The New York Times' website outage Wednesday morning has led to speculation that the newspaper may have been the victim of a cyberattack.

The Times disclosed in May that its website had suffered a distributed denial-of-service attack that resulted in limited access to articles for some users. In a denial-of-service attack, hackers typically take control of personal computers by infecting them with a virus. Then, they order these computers to load the same website simultaneously over and over again.

The databases and servers that store all of a website’s information become overloaded and start “denying service” to some users.

At the time, New York Times spokeswoman Danielle Rhoades Ha said the company did not “have confirmation on who is responsible for the most recent attacks on nytimes.com.”

Wednesday’s shutdown affected the newspaper's mobile apps and its company email service, a potential sign that the issue may not have been related to a cyberattack but some sort of widespread malfunction. On Twitter, the New York Times cited an “internal issue.”

Last year, the New York Times’ computer network was breached by a Chinese hacking group. The hackers dug up passwords for the newspaper’s employees as part of the attack. Wednesday’s issue comes just two days after the cybersecurity firm FireEye said the hacking group, referred to as APT 12, had resumed attacks in May. The group had been quiet for several months after the New York Times exposed the group.

On Wednesday, FireEye said it was still researching what might have caused the Times’ website to go down.

[Updated, 11:20 a.m. Aug. 14: Mandiant, a cybersecurity firm that has worked with the New York Times Co. previously, said it was unable to speculate about the potential cause of the outage.]

During the outage, the New York Times said it would post what it called “key news articles” in their entirety on Facebook. At least three articles had been posted.